Out board motor help?

[Glenn Basore]

Hi all,

I think I need to replace the impeller ( water pump ?) on my 2005 Mercury four stroke / 4 horse power. The water discharge flow has seem to diminished compared to its usual flow.  Some times it's stops for a few seconds before the water flow starts up again, this is usually at idel. At run speeds, the flow is there, just not as strong as before.

I sail in salt water, I don't know if the water passeges have become clogged with the salt, is there an additive  I can use to flush the passages?  I do flush immediately after pulling the boat out of the water.

Is changing the impeller a difficult job?  I've never worked on an outboard before other than changing plug and filt.

Cost of impeller vs having it done?

Glenn

[Shawn]

Glenn,

Last fall I changed out the impeller on my Tohatsu Sailpro. It is an easy job. The impeller costs $19 at Defender.

In a nutshell you basically are removing the lower unit from the outboard and that exposes the impeller.

An example is at:
http://casterbaiter.com/how-to-install-nissan-tohatsu-outboard-engine-water-pump-impeller-step-by-step-guide/

On the Sailpro there is a large rubber disc on the side of the leg near the lower unit. That comes off and it exposes the gear shift linkage. You have to loosen that bolt to allow the shifter to disengage. Then it is just removing the bolts that hold the lower unit on and then taking the cover off the impeller housing. Then you  swap out the impeller (watch for the pin) and reassemble. Maybe took an hour or two.

Shawn

[Glenn Basore]

Thanks Shawn,

I think I will try doing the work my self after reading your reply and link to read.

Glenn

[ssullivan]

its ALWAYS better to change the impeller than to risk a overheated motor. I have always ran boats in salt water never really had a build up of salt in the cooling passages have had them get full of, mud, sand, seaweed, plastic, bits of impeller(the worst!) and if you don't use it enough mud dobber wasps. I have used SaltX after outboards have sunk and it works well to get the salt out of the block if you let it sit for long periods of time you can try that. hope that helps

Stephen

[Glenn Basore]

Thanks Stephen and others,

I'm guessing its the impeller which I've never changed. Although it a 2005 out board on my 2006 Eclipse, there really isn't that many hours on it. I only use it to get around the docks.

Some time ago on this site I complained how bad the motor was running and never did idle right. With several suggestions to use Sea Foam which I did with great results, it now runs better than it ever has, really smoth and no misses .

So, I will change the impeller soon than later and it should be pretty good at that point. As to the SaltX , I run my OB in a 50 gallon tank to flush it out,  how long would it have to sit in my tank or can I just flush it using Salt X ?

Glenn

[moonlight]

If you want the motor to take care of you, you've got to take care of the motor.

Look in your book.  I betcha gear oil, impeller, thermostat, and spark plugs are annual items, if not twice annually.

Sure, lots of people stretch that to two years without damage.  Flushing is advised also, and beneficial.

But the only thing you get out of going beyond a two year interval is practice sailing back to the dock.